This invention relates to a measurement device for golf clubs, and, more particularly, to a device for measuring the length, lie, and loft of a golf club as well as many other fitting variables.
There are many important variables in a golf club which affect the playability of the club in the hands of a particular player. Some of those variables are shaft length, lie, and loft. Shaft length is a measurement of the length of the club. Lie is the angle between the centerline of the shaft and the clubhead. Loft is the angle between the plane of the face of the clubhead and a vertical plane which extends through the centerline of the shaft. Although the terms, length, lie, and loft are standard terms in the golf club industry, the terms do not always mean the same thing, and there are no standard procedures for measuring those variables.
Various devices have been used for facilitating the measurement of golf clubs. Such devices include length boards, Sung Fung gauges, center golf gauges, and Dela Cruse gauges. A length board is used by laying the club on the board and using a ruler along the back side of the club. Although this is a relatively convenient way to measure length, it has some fundamental shortcomings. For example, the length reading is dependent on the lie and the hosel diameter since these gauges are based on the assumption that the touch point on the sole of the club is the same distance from the shaft centerline for all clubs in the set and for all sets.
The book entitled "The Complete Golf Club Fitting Plan, Fitting Variable #4 Club Length," by Ralph Maltby states that the best and most accurate method for measuring a golf club is to measure the distance between the end of the club shaft and the point at which the centerline of the shaft passe through the ground plane. However, the measurement procedure which is described in the book does not precisely measure that dimension. The book states that the easiest way to measure clubs is to set the club in the correct lie position and place a rigid ruler behind the club and touching the heel. Because the ruler is displaced from the centerline of the shaft, the bottom of the ruler does not extend as far as the point at which the centerline of the shaft passes through the ground plane. Also, the book does not describe any fixture or apparatus for positioning the club with respect to a fixed reference point.
The Sung Fung and Dela Cruse gauges have a pivot point which is not in the ground plane. Accordingly, as the shaft pivots, the position of the end of the shaft changes relative to the ground plane.